Researchers create chemicals and biofuel from biomass

Dec. 20, 2011, Aalto, FI – Researchers at Aalto University in Finland
have patented a way to extract raw materials in wood biomass for
transformation into chemicals and biofuel.

The most commonly used raw materials in butanol production have so far
been starch and cane sugar. In contrast to this, the starting point in
the Aalto University study was to use only lignocellulose, otherwise
known as wood biomass, which does not compete with food production.

Another new breakthrough in the study is to successfully combine
modern pulp – and biotechnology. Finland's advanced forest industry
provides particularly good opportunities to develop this type of
bioprocesses.

Wood biomass is made up of three primary substances: cellulose,
hemicelluloses and lignin. Of these three, cellulose and hemicellulose
can be used as a source of nutrition for microbes in bioprocesses. Along
with cellulose, the Kraft process that is currently used in pulping
produces black liquor, which can already be used as a source of energy.
It is not, however, suitable for microbes. In the study, the pulping
process was altered so that, in addition to cellulose, the other sugars
remain unharmed and can therefore be used as raw material for microbes.

When wood biomass is boiled in a mixture of water, alcohol and
sulphur dioxide, all parts of the wood – cellulose, hemicellulose and
lignin – are separated into clean fractions. The cellulose can be used
to make paper, nanocellulose or other products, while the hemicellulose
is efficient microbe raw material for chemical production. Thus, the
advantage of this new process is that no parts of the wood sugar are
wasted.

In accordance with EU requirements, all fuel must contain 10 per
cent biofuel by 2020. A clear benefit of butanol is that a significantly
large percentage – more than 20 per cent of butanol, can be added to
fuel without having to make any changes to existing combustion engines.
The nitrogen and carbon emissions from a fuel mix including more than 20
per cent butanol are significantly lower than with fossil fuels. For
example, the incomplete combustion of ethanol in an engine produces
volatile compounds that increase odour nuisances in the environment.

Estimates indicate that combining a butanol and pulp plant into a modern
biorefinery would provide significant synergy benefits in terms of
energy use and biofuel production.